Liquid dispensing pump



May 22, 1962 A. w. FREEMAN 3,035,743

LIQUID DISPENSING PUMP Filed Sept. 15, 1958 2 Sheets-Sheet 1 I71 Van or: Awbrosc William Freon-n lt/ d, mi' (PM b3 W Rttgs.

May 22, 1962 w. FREEMAN 3,035,743

LIQUID DISPENSING PUMP Filed Sept. 15, 1958 2 Sheets-Sheet 2 CL. v Mfo r.- AM bro 5 William Frccmm I WWM,%+ (PM United States Patent Oflfice 3,035,743 Patented May 22, 1952 3,035,743 LIQUID DISPENSING PUMP Ambrose William Freeman, Sydney, New South Wales, Australia Filed Sept. 15, 1958, Ser. No. 760,960 Claims prio 'ty, application Australia Oct. 2, 1957 3 Claims. (Cl. 222-341) This invention relates to equipment used in garages and like places for dispensing liquids such as lubricating oils from bulk supplies in relatively small accurately measured quantities.

Existing equipment for this purpose includes a bulk supply of liquid, means for transferring a predetermined quantity of liquid from the bulk supply to a discharge spout or outlet, a valve on the spout and means for closing the valve when the required quantity has been discharged through the spout.

Difficulty has been experienced in completing the last stage of closing of the valve. As a result liquid may continue to drip through the spout for some time after the intended time of valve closure.

This leads to inaccurate dispensing and inconvenience caused by dripping after use.

The object of the present invention is to provide apparatus substantially free from this defect.

In a general form the invention is a pump adapted to draw liquid from a bulk supply, a discharge pipe leading from the pump, a discharge chamber connected to the pipe near its outlet end, an outlet from the discharge chamber, a valve on the outlet and means for rapidly reducing the pressure in the pipe for closing the outlet valve when the required amount of liquid drawn from the bulk supply has been dispensed through the outlet.

A preferred form of the apparatus is illustrated in the accompanying drawings, in which:

FIG. 1 is a front elevation with the lower portion of the pump body partially shown in half section, and

FIG. 2 is a sectional view along line 2-2 of FIG. 1 showing the linkages in elevation.

The apparatus is in three main parts, a pump proper 3 and a discharge chamber 4 connected by a pipe 5. The latter is connected at One end to the upper end 6 of the pump body 3 and extends upwards and then horizontally. It is sufliciently strong to carry the discharge chamber 4 on its other end 7.

The pump body 3 is in two hollow parts 8 and 9. The lower part 9 has a floor 1t} and a wall 11 and an outwardly flanged open upper end 12. The upper part 8 is domed and has an outwardly flanged open lower end 13. The parts 8 and 9 are connected across their open ends by their flanges 12 and 13. A vertical cylindrical passage 14 is formed through the floor 19 of the lower body part 9. The upper end of a second pipe 15 is fitted into an enlarged lower end 16 of the passage 14 and extends into a reservoir of oil (not shown) on the top of which the pump 3 is mounted.

A radially webbed plunger 17 slides in the passage 14 and in the second pipe 15. On its upper end it carries a frusto conical valve head 13 adapted to seat on a corresponding valve seat 19 formed around the upper end of the passage 14. The webs 2t and the passage 14 guide the plunger 17.

A clearance is provided between the webs 2i! and the bore of the second pipe 15 and a compression spring 21 is accommodated therein so that its upper end bears against the step 22 forming the junction between the passages 14 and 16, and its lower end bears against a radial pin 23 secured to the lower end 24 of the webbed plunger 17. The conical valve head 18 is thus spring loaded against its seat 19.

A piston 25 is slidably mounted in fluid tight fashion in the pump body upper part 8 and a passage 26 is ioimed through the piston.

The passage 26 is narrowest near its underside where a seat 27 is provided for a ball valve 28 located above the seat and below a cross pin 29.

Two links 30 and 31 are pin connected together at one end 32 within the body 3, the upper one 31 being pin connected at 33 at its other or upper end to the underside of the piston 25, and the lower one 39 being pin connected at 34 at its other or lower end to the foot valve plunger 17 An operating link 35 is pin connected to the piston and plunger links 30 and 31 at their common connection 32 and at its other end it is fast on a cross shaft 36 mounted on and between the pump walls 11. The cross shaft extends outside the pump body and is bent at right angles to form an integral pump arm 37 by means of which it may be rotated.

A stud 38 is screwed through the pump wall 11 and engages the operating link 35 so as to limit its rotation in the direction moving the piston 25 upwards. The stud position may be varied within narrow limits so as to meter accurately the upward movement of the piston 25 and therefore the amount of liquid dispensed. A lock nut 39 is provided on the stud so that it may be locked in a selected position.

The discharge chamber 4 is an upright cylinder closed at its upper end by a detachable cap 40 with a hole 41 through it, and having a short discharge spout 42 at its lower end. The cylinder 4 is connected to the first pipe 5 through its wall near the spout 42.

A second piston 43 is slidably mounted in fluid tight fashion in the cylinder upper end and has a stem 44 secured to its underside having a frusto conical lower end forming a valve head 45 and adapted to seat on a corresponding seat 46 formed on the upper or inner end of the spout 42.

In use initially the foot valve 18 and the discharge spout valve 45 are closed. The pump body 3, the pipe 5 and the discharge chamber 4 below its piston 43 are filled with liquid. The pump piston 25 is down under the influence of the spring 21.

The operation of the pump is brought about by first moving the pump arm 37 clockwise as seen in FIG. 2. This swings link 35 upwardly, which in turn pushes piston 25 up and draws plunger 17 out of passage 14. When link 35 abuts stud 38, the pump arm 37 is released. Spring 21, which has been compressed during the lifting of plunger 17, draws plunger 17 down, which in turn draws links 36 and 35 down. Piston 25 is likewise drawn down by link 31.

During the upward movement of the piston 25 by movement of the lever 37, pressure is developed in the liquid in the pipe 5 and the piston 43 is upwardly displaced, opening the valve 45, 46, and permitting liquid to flow through the opening '42. The diameter of the opening 42 is inadequate to permit the full flow of the displacement of the piston 25 without causing appreciable back pressure to be built up under the piston 43. Thus the piston 43 is driven to the extremity of its travel thus fully opening the valve 45, 46.

At the end of the upward movement of the piston 25, flow through the pipe 5 ceases and the back pressure brought about by the resistance to flow through the opening 42 falls to zero and the piston 43 then commences to descend and the fluid displaced by its downward movement freely leaves the system through the opening 42 un til the downward movement of the piston 43 has closed the space past the valve seating 46 to a point where material resistance to flow occurs. This resistance causes a fall in the rate of descent of the piston 43 and as further fluid flows through the opening between 45 and 46 the resistance to flow increases. Thus this ever increasing resistance to flow through the valve causes an accompanying decrease in the rate of descent of the piston 43.

Upon release of the operating lever 37 the spring 21 causes the piston 25 under its influence to move in a downward direction. Initially it is free to move in a downward direction due to the volume of liquid available to the system above the piston 25 representing uncompleted displacement of the piston 43. The initial movement of the piston is quite small and depends on the relative dimensions of the pistons 25 and 43. During this initial movement the valve 28 remains closed and the displacement of the piston 25 equal to the displacement of piston 43 leaves the system through the passage 14. During the downward movement of the piston 25 and the displacement of fluid from the system through the passage 14, the closing of the valve 45 is not in any way delayed by the resistance to flow through the aperture at as as the displacement of the piston 43 is removed from the system through the opening 14 rather than through opening 42, but upon completion of the downward movement of the piston 43, the influence of the spring 21 causes the pressure above the piston 25 to fall below that of the pressure below the piston 25. Thus flow occurs through the valve 28 but there is no further displacement of fiaid through the passage 14 resulting from the downward movement of the piston 25, the pressure existing on the underside of the piston 25 representing atmospheric pres sure upon the liquid in the bulk supply container. Upon completion of the downward stroke of the piston 25 closure of the valve 18 upon its seat 19 occurs. At this stage the pipe 7, the chamber 4 and the space 6 above the piston 25 and the whole of the space below the piston 25 are full of liquid which cannot drain from the system due to the valve 18, 19 being closed.

The pump is self priming. Initially, with the chamber 4 and pipe 5 and the space 6 in the pump body 3 above the piston 25 full of air, repeated strokes of the lever 37 raising and lowering the piston 25 will graduaily displace the air through the spout 42 and the displaced air will be gradually replaced by liquid passing through the valve 28 to above the piston.

In an alternative construction of the valve 17, 18, 25, it is a half ball, spherical side downwards, adapted to seat on the seat 19, linked by pins such as 32, 33, 34 and links 30, 31 to the piston 25 and biassed downwards by a tension spring connected at its ends to the half ball and to the bottom of the pipe 15.

In such a case, on release of the arm 37, the action of the tension spring will be similar to that of the spring 21, as described earlier, in enabling a quick and sharp final closure'of the valve 45.

Preferably the pin connection at 33 is such that the holes 33A in spaced lugs 333 secured to the underside of the piston 25 are slotted or enlarged as shown. This d. delays the lifting of the piston 25 momentarily after the foot valve moves off its seat.

In a modification the valve stem 44 is extended with a close fit through the spout '42 so that, in the fully closed position, the bottom of the extension is flush with t.e bottom of the spout.

What I claim is:

1. In combination a hollow pump body, a passageway connecting one end of the body to a bulk supply of liquid, a valve member displaceable in the passageway for opening and closing the passageway, a first piston displaceable in substantially fiuid tight fashion in the other end of the body and linked to the valve member, means biassing the valve member to the passageway closing position, displacing means on said body and linked to said first piston and valve member for displacing the valve member and first piston together in the body against the biassing means, a pipe connected to the body on the side of the first piston remote from the valve member, said first piston having a passage therethrough, a check valve in the piston passage for substantially preventing liquid flow from the pipe side to the valve member side of the piston and to allow reverse flow, a discharge chamber on the other end of said pipe, a second piston slidable in substantially fluid tight fashion in the chamber, said chamber having a discharge outlet, and a valve head carried by the second piston and normally adapted to close the outlet, the chamber being connected between the second piston and its outlet to the other end of the pipe and having an outlet to the atmosphere on the opposite side of said second piston from said valve head.

2. A combination as in claim 1 wherein the valve member is elongated and has a length such that the body passageway remains open until near the end of the return movement of the valve member under the influence of the biassing means.

3. A combination as in claim 1 wherein the valve 1 ember and said first piston are linked by a linkage having a loose connection to said first piston such that displacement of the valve member by the displacing means commences a short time before corresponding displacement of the first piston.

References Cited in the file of this patent UNITED STATES PATENTS 29,266 Holly July 24, 186 195,253 Barnes Sept, 18, 1877 1,548,120 Dourson Aug. 4, 1925 1,871,444 Godrington Aug. 16, 1932 FOREIGN PATENTS 5,911 Great Britain of 1882 17,023 Great Britain of 1894 23,448 Great Britain of 1902 152,026 Australia Dec. 7, 

